Profile and in-plane structures of self-assembled monolayers on germanium/silicon multilayer substrates by high-resolution x-ray diffraction employing x-ray interferometry/holography

Abstract

X-ray interferometry has been used to study the profile structures of chemisorbed alkylsiloxane (hexadecyl-, octadecyl-, and eicosyl-) monolayer films on Ge/Si multilayer substrates of the type 2(Ge 2 Si 30 ), i.e., two superlattice unit cells, each consisting of 2 Ge monolayers and 30 Si monolayers, as fabricated by molecular beam epitaxy (MBE). Analysis was performed in three steps. First, based on the structural specifications of the cleaned, bare substrates acquired form the MBE fabrication, the actual profiles structures of selected multilayer substrates were determined via a model refinement analysis of their meridional X-ray diffraction